This study will evaluate the safety and efficacy of Indium 111 pentetreotide in high doses (180mci) for treatment of somatostatin expressing neoplasms which are resistant to or have failed standard therapy. The subjects will receive this radioactive-somatostatin analog, normally used for scanning in low doses. It will be administered intravenously with subsequent dosimetry to assess the body's response to the new agent. Blood work and urine collections will be obtained to provide information about the levels of radioactivity remaining in the body. The patient will also be seen in the nuclear medicine department for scanning to assess radioactive levels.